十枚长得一样的硬币,其中九枚正反朝上的概率都是50%,但是另一枚硬币正面朝上的概率为90%。从中随便选出一枚硬币,抛了七次,七次都是正面朝上,那么请问选到那枚正面朝上为90%的硬币概率是多少?
A bag contains 9 fair coins and 1 biased coin (where the probability of heads is 0.9). You draw a coin at random from the bag, toss it 7 times and get 7 heads. What is the probability that the coin sampled is the biased one?
A bag contains 9 fair coins and 1 biased coin (where the probability of heads is 0.9). You draw a coin at random from the bag, toss it 7 times and get 7 heads. What is the probability that the coin sampled is the biased one?